It's not just Madonna and Liz Hurley who are doing Pilates.

British tennis player Elena Baltacha has become the latest convert using the technique to nurse her back from injury.

Pilates has been around for 70 years but even members of the New Zealand All Blacks have used it as part of their training.

Here we give you an idea of what all the fuss is about.

What is Pilates?

Pilates (pronounced pi-lah-tees) is a form of exercise which build's your body's core strength and posture.

This is done through a series of stretching and conditioning exercises.

Think of holding your arms out to your side for as long as you can. Or sitting down with your legs out in front of you and raising them just above the floor.

Pilates uses these types of exercises which are great for your muscles and help prevent injury.

Where does the name come from?

Pilates is the idea of Joseph Pilates who was born in Germany in 1880.

As a child he was frequently ill and decided to train himself using gymnastics to improve his health.

The rolling ball

He was a bit of a health guru and studied Yoga and Tai Chi before inventing his own brand of exercise in the early 1900's.

In many ways he was ahead of his time and used his techniques to help dancers who were recovering from injury.

But his methods were so successful that all sorts of people now use them from ballet dancers through to rugby players.

How do you do it?

Pilates is practised on a mat and is mostly taught in a class but there is specialist equipment available too.

At first you learn the importance of movement with breathing.

As you get better, exercises are combined to create a flowing continuous movement.

Any tips for starting?

Pilates classes run up and down the country in hundreds of health and fitness clubs.

There are lots of different versions of Pilates so you can adapt it to suit you.

Make sure you have an experienced instructor and don't be afraid to ask them why you are doing a certain exercise.

The fewer people in the class the more attention your teacher will be able give you!

For more information click on the links on the right hand side of the page.